Dataset Information

Sacubitril/Valsartan Improves Left Ventricular Function in Chronic Pressure Overload Independent of Intact Cyclic Guanosine Monophosphate-dependent Protein Kinase I Alpha Signaling.

ABSTRACT:

Background

Combined angiotensin receptor/neprilysin inhibition with sacubitril/valsartan (Sac/Val) has emerged as a therapy for heart failure. The presumed mechanism of benefit is through prevention of natriuretic peptide degradation, leading to increased cyclic guanosine monophosphate (cGMP)-dependent protein kinase (PKG) signaling. However, the specific requirement of PKG for Sac/Val effects remains untested.

Methods and results

We examined Sac/Val treatment in mice with mutation of the cGMP-dependent protein kinase I (PKGI)α leucine zipper domain, which is required for cGMP-PKGIα antiremodeling actions in vivo. Wild-type (WT) or PKG leucine zipper mutant (LZM) mice were exposed to 56-day left ventricular (LV) pressure overload by moderate (26G) transaortic constriction (TAC). At day 14 after TAC, mice were randomized to vehicle or Sac/Val by oral gavage. TAC induced the same degree of LV pressure overload in WT and LZM mice, which was not affected by Sac/Val. Although LZM mice, but not WT, developed LV dilation after TAC, Sac/Val improved cardiac hypertrophy and LV fractional shortening to the same degree in both the WT and LZM TAC mice.

Conclusion

These findings indicate the beneficial effects of Sac/Val on LV structure and function in moderate pressure overload. The unexpected finding that PKGIα mutation does not abolish the Sac/Val effects on cardiac hypertrophy and on LV function suggests that signaling other than natriuretic peptide- cGMP-PKG mediates the therapeutic benefits of neprilysin inhibition in heart failure.

SUBMITTER: Tam K

PROVIDER: S-EPMC7529795 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:BackgroundThe ratio of ucGMP (urinary cyclic guanosine monophosphate) to BNP (B-type natriuretic peptide) is thought to reflect the responsiveness of tissues to natriuretic peptides.MethodsWe examined the relationship between ucGMP/BNP ratio and clinical outcomes, the effect of sacubitril/valsartan, compared with enalapril, on the ucGMP/BNP ratio, and the efficacy of sacubitril/valsartan on clinical outcomes according to baseline ucGMP/BNP ratio in PARADIGM-HF trial (Prospective Comparison of ARNI With ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure). ucGMP/BNP ratio was available at baseline (N=2031), 1 month (N=1959), and 8 months after randomization (N=1746). The primary outcome was a composite of heart failure hospitalization or cardiovascular death.ResultsCompared with the lowest tertile of baseline ucGMP/BNP ratio, patients in the higher tertiles had a lower risk of the primary outcome (tertile 1, reference; tertile 2, hazard ratio 0.57 [95% CI, 0.45-0.71]; tertile 3, hazard ratio, 0.54 [0.43-0.67]). Compared with baseline, the ucGMP/BNP ratio at 1 month and 8 months after randomization was higher with sacubitril/valsartan than with enalapril: ratio of geometric mean ratios at 1 month, 1.38 (95% CI, 1.27-1.51) and 8 months, 1.32 (95% CI, 1.20-1.45), and this difference was consistent across tertiles of ucGMP/BNP ratio at baseline (Pinteraction=0.19 and 0.91, respectively). The effect of sacubitril/valsartan, compared with enalapril, was consistent across tertiles of ucGMP/BNP ratio at baseline for all outcomes (Pinteraction ≥0.31).ConclusionsIn patients with heart failure and reduced ejection fraction, higher ucGMP/BNP ratio was associated with better outcomes. Sacubitril/valsartan increased the ucGMP/BNP ratio, compared with enalapril, and the effect of sacubitril/valsartan on clinical outcomes was not modified by baseline ucGMP/BNP ratio.RegistrationURL: https://www.Clinicaltrialsgov; Unique Identifier: NCT01035255.

Project description:AimsIdentifying early right ventricular (RV) dysfunction and impaired vasodilator reserve is challenging in heart failure with preserved ejection fraction (HFpEF). We hypothesized that cardiac magnetic resonance (CMR)-based exercise imaging and serial cyclic guanosine monophosphate (cGMP) measurements can identify dynamic RV-arterial uncoupling and responsiveness to pulmonary vasodilators at early stages of the HFpEF syndrome.Methods and resultsPatients with HFpEF (n = 16), impaired left ventricular relaxation due to concentric remodelling (LVCR, n = 7), and healthy controls (n = 8) underwent CMR at rest and during supine bicycle exercise with simultaneous measurements of central haemodynamics and circulating cGMP levels, before and after oral administration of 50 mg sildenafil. At rest, mean pulmonary artery pressures (mPAP) were higher in HFpEF, compared with LVCR and controls (27 ± 2, 18 ± 1, and 11 ± 1, respectively; P = 0.01), whereas biventricular volumes, heart rate, and stroke volume were similar. During exercise, LVCR and HFpEF had a greater increase in the ratio of mPAP over cardiac output than controls (5.50 ± 0.77 and 6.34 ± 0.86 vs. 2.24 ± 0.55 in controls, P = 0.005). The ratio of peak exercise to rest RV end-systolic pressure-volume, a surrogate of RV contractility, was significantly reduced in LVCR and HFpEF (2.32 ± 0.17 and 1.56 ± 0.08 vs. 3.49 ± 0.35 in controls, P < 0.001) and correlated with peak exercise VO2 (R2 = 0.648, P < 0.001). cGMP levels increased with exercise across the HFpEF spectrum (P < 0.05 vs. baseline), except when postcapillary pulmonary hypertension was present at rest (P = 0.73 vs. baseline). A single sildenafil administration failed to increase circulating cGMP levels and did not improve RV performance.ConclusionExercise CMR identifies impaired RV-arterial coupling at an early stage of HFpEF. Circulating cGMP levels phenocopy the haemodynamic spectrum in HFpEF but fail to increase after phosphodiesterase type 5 inhibition, endorsing the need for alternative interventions to increase cGMP signalling in HFpEF.